Editing Corynebacterium (section)

== Characteristics ==
The principal features of the genus ''Corynebacterium'' were described by Collins and Cummins, for Coryn Taylor in 1986.<ref name=collins>{{cite book |last1=Collins |first1=M. D. |last2=Cummins |first2=C. S. |year=1986 |chapter=Genus Corynebacterium Lehmann and Neumann 1896, 350AL |title=Bergey's Manual of Systematic Bacteriology |volume=2 |pages=1266–76 |editor1-first=P. H. A. |editor1-last=Sneath |editor2-first=N. S. |editor2-last=Mair |editor3-first=M. E. |editor3-last=Sharpe |editor4-first=J. G. |editor4-last=Holt |location=Baltimore |publisher=Williams & Wilkins }}</ref> They are gram-positive, [[catalase]]-positive, non-[[spore]]-forming, non-[[motility|motile]], rod-shaped bacteria that are straight or slightly curved.<ref name=glaucum>{{cite journal |doi=10.1099/ijs.0.02394-0 |pmid=12807190 |title=''Corynebacterium glaucum'' sp. nov |journal=International Journal of Systematic and Evolutionary Microbiology |volume=53 |issue=3 |pages=705–9 |year=2003 |last1=Yassin |first1=A. F. |doi-access=free }}</ref> [[Metachromatic granules]] are usually present representing stored phosphate regions. Their size falls between 2 and 6 [[micrometre|μm]] in length and 0.5 μm in diameter. The bacteria group together in a characteristic way, which has been described as the form of a "V", "palisades", or "Chinese characters". They may also appear [[ellipse|elliptical]]. They are [[Aerobic organism|aerobic]] or [[Facultative anaerobic organism|facultatively anaerobic]], [[chemoorganotroph]]s. They are [[pleomorphism (microbiology)|pleomorphic]] through their [[Biological life cycle|lifecycles]], they occur in various lengths, and they frequently have thickenings at either end, depending on the surrounding conditions.<ref>{{cite journal |doi=10.1111/j.1365-2672.1977.tb00689.x |pmid=406255 |title=The Cell Wall Composition and Distribution of Free Mycolic Acids in Named Strains of Coryneform Bacteria and in Isolates from Various Natural Sources |journal=Journal of Applied Bacteriology |volume=42 |issue=2 |pages=229–52 |year=1977 |last1=Keddie |first1=R. M. |last2=Cure |first2=G. L. }}</ref>

Some corynebacteria are [[lipophilic bacteria|lipophilic]] (such as [[CDC coryneform]] groups F-1 and G, ''[[Corynebacterium accolens|C. accolens]]'', ''[[Corynebacterium afermentans|C. afermentans]]'' subsp. ''lipophilum'', ''[[Corynebacterium bovis|C. bovis]]'',<ref name=cmr/> ''[[Corynebacterium jeikeium|C. jeikeium]]'', ''[[Corynebacterium macginleyi|C. macginleyi]]'', ''[[Corynebacterium uropygiale|C. uropygiale]]'',<ref name="Braun"/> and ''[[Corynebacterium urealyticum|C. urealyticum]]''), but medically relevant corynebacteria are typically not.<ref>{{Cite journal |last=Bernard |first=Kathryn |date=2012 |title=The Genus Corynebacterium and Other Medically Relevant Coryneform-Like Bacteria |url=https://journals.asm.org/doi/10.1128/JCM.00796-12 |journal=Journal of Clinical Microbiology |language=en |volume=50 |issue=10 |pages=3152–3158 |doi=10.1128/JCM.00796-12 |issn=0095-1137 |pmc=3457441 |pmid=22837327}}</ref> The nonlipophilic bacteria may be classified as [[fermentation (biochemistry)|fermentative]] (such as ''[[Corynebacterium amycolatum|C. amycolatum]]''; ''[[Corynebacterium argentoratense|C. argentoratense]]'', members of the ''[[Corynebacterium diphtheriae|C. diphtheriae]]'' group, ''[[Corynebacterium glucuronolyticum|C. glucuronolyticum]]'', ''[[Corynebacterium glutamicum|C. glutamicum]]'', ''[[Corynebacterium matruchotii|C. matruchotii]]'', ''[[Corynebacterium minutissimum|C. minutissimum]]'', ''[[Corynebacterium striatum|C. striatum]]'', and ''[[Corynebacterium xerosis|C. xerosis]]'') or nonfermentative (such as ''[[Corynebacterium afermentans|C. afermentans]]'' subsp. ''afermentans'', ''[[Corynebacterium auris|C. auris]]'', ''[[Corynebacterium pseudodiphtheriticum|C. pseudodiphtheriticum]]'', and ''[[Corynebacterium propinquum|C. propinquum]]'').<ref name=cmr>{{cite journal |pmid=8993861 |pmc=172946 |year=1997 |last1=Funke |first1=G |title=Clinical microbiology of coryneform bacteria |journal=Clinical Microbiology Reviews |volume=10 |issue=1 |pages=125–59 |last2=von Graevenitz |first2=A |last3=Clarridge Je |first3=3rd |last4=Bernard |first4=K. A. |doi=10.1128/CMR.10.1.125 }}</ref>

=== Cell wall ===
The [[cell wall]] is distinctive, with a predominance of [[mesodiaminopimelic acid]] in the [[murein]] wall<ref name=caspium /><ref name=glaucum /> and many repetitions of [[arabinogalactan]], as well as corynemycolic acid (a [[mycolic acid]] with 22 to 26 [[carbon]] atoms), bound by [[disaccharide]] bonds called [[L-Rhap|L-Rha''p'']]-(1 → 4)--D-GlcNAc-phosphate. These form a complex commonly seen in ''Corynebacterium'' species: the mycolyl-AG–peptidoglican (mAGP).<ref>{{cite journal |doi=10.1093/glycob/cwl066 |pmid=17088267 |title=Topology and mutational analysis of the single Emb arabinofuranosyltransferase of Corynebacterium glutamicum as a model of Emb proteins of Mycobacterium tuberculosis |journal=Glycobiology |volume=17 |issue=2 |pages=210–9 |year=2006 |last1=Seidel |first1=M. |last2=Alderwick |first2=L. J. |last3=Sahm |first3=H. |last4=Besra |first4=G. S. |last5=Eggeling |first5=L. |doi-access=free }}</ref> Unlike most corynebacteria, ''[[Corynebacterium kroppenstedtii]]'' does not contain mycolic acids.<ref>{{cite journal |doi=10.1099/00207713-48-4-1449 |pmid=9828448 |title=Note: ''Corynebacterium kroppenstedtii'' sp. nov., a novel corynebacterium that does not contain mycolic acids |journal=International Journal of Systematic Bacteriology |volume=48 |issue=4 |pages=1449–54 |year=1998 |last1=Collins |first1=M. D. |last2=Falsen |first2=E. |last3=Akervall |first3=E. |last4=Sjoden |first4=B. |last5=Alvarez |first5=A. |display-authors=3|doi-access=free }}</ref>

=== Culture ===
Corynebacteria grow slowly, even on enriched media. In nutritional requirements, all need [[biotin]] to grow. Some strains also need [[thiamine]] and [[4-aminobenzoic acid|PABA]].<ref name=collins /> Some of the ''Corynebacterium'' species with sequenced genomes have between 2.5 and 3.0 million base pairs. The bacteria grow in [[Löffler's serum|Loeffler's medium]], [[blood agar]], and [[trypticase soy agar]] (TSA). They form small, grayish colonies with a granular appearance, mostly translucent, but with opaque centers, convex, with continuous borders.<ref name=glaucum /> The color tends to be yellowish-white in Loeffler's medium. In TSA, they can form grey colonies with black centers and dentated borders that either resemble flowers (''C. gravis''), continuous borders (''C. mitis''), or a mix between the two forms (''C. intermedium'').{{citation needed|date=February 2023}}